Revision as of 05:59, 5 January 2006

Lossless compression explained

Lossless compression is a compression methodology in which the result of the compression can be restored faithfully, i.e. bit-by-bit identical with the uncompressed data.

In a nutshell, it is somewhat like compressing a Waveform file with ZIP or RAR.

The difference between 'mere' ZIP/RAR is that lossless compression algorithms are especially tuned and designed for the characteristics of Waveform data, thus achieving compression far greater than can be achieved by generic compression utilities.

Popular lossless formats

Apple Lossless (ALAC)

FLAC

Lossless Audio (LA)

LPAC

MLP

Monkey's Audio (APE)

OptimFROG

RKAU

Shorten (SHN)

TTA

WavPack

WMA lossless

Oddball Formats

There are several old lossless formats that aren't really deserving of having an article all for themselves. Reasons are: lack of widespread support, lack of features, bad efficiency and, most importantly, it seems noone is really interested in them.

Most of those would have disappeared by now, but they are being preserved for posterity at rjamorim's ReallyRareWares

Advanced Digital Audio (ADA)

http://www.rjamorim.com/rrw/ada.html

Marian's a-Pac

AudioZip

http://www.rjamorim.com/rrw/audiozip.html

Dakx WAV

Entis Lab MIO

LiteWave

Pegasus SPS

RKaudio

Split2000

http://www.rjamorim.com/rrw/split2000.html

Sonarc

http://www.rjamorim.com/rrw/sonarc.html

VocPack

http://www.rjamorim.com/rrw/vocpack.html

WavArc

http://www.rjamorim.com/rrw/wavarc.html

WaveZip/MUSICompress

Note that currently no single format can be considered best for all applications. Rather, the best format depends on the intended use, as well as a number of other factors (such as licensing and file structure). For example, Shorten and FLAC are widely used for sharing live music because of their cross-platform support and speed. Monkey's Audio is popular among Windows users for its superior compression ratio.

Lossless compressors comparisons (note the specific assumptions and limitations of each comparison; in particular, results are sensitive to the music selected):

http://web.inter.nl.net/users/hvdh/lossless/lossless.htm: Includes an interesting graph of encode/decode speeds vs. file size on the All Albums page

Lossless comparison: A comparision focusing more on codec features and less on absolute encoding efficiency. Also features a table comparing most popular codecs based on their features.

http://home.wanadoo.nl/~w.speek/comparison.htm: Performance Comparison of Lossless Audio Compressors - Compares file size, encode speed, decode speed for APE, FLAC, LPAC, WavPack, Shorten (SHN), RKAU, OptimFROG, LA, WMA Lossless. Updated 5-2003

@@ Line 1: / Line 1: @@
 =Lossless compression explained=
+'''Lossless compression''' is a compression methodology in which the result of the compression can be restored faithfully, i.e. bit-by-bit identical with the uncompressed data.
+In a nutshell, it is somewhat like compressing a Waveform file with ZIP or RAR.
+The difference between 'mere' ZIP/RAR is that lossless compression algorithms are especially tuned and designed for the characteristics of Waveform data, thus achieving compression far greater than can be achieved by generic compression utilities.
@@ Line 26: / Line 32: @@
 * [[WMA | WMA lossless]]
 ==Oddball Formats==
 There are several old lossless formats that aren't really deserving of having an article all for themselves. Reasons are: lack of widespread support, lack of features, bad efficiency and, most importantly, it seems noone is really interested in them.
 Most of those would have disappeared by now, but they are being preserved for posterity at [[User:Rjamorim|rjamorim]]'s [http://www.rjamorim.com/rrw/ ReallyRareWares]
 ; Advanced Digital Audio (ADA)
@@ Line 94: / Line 99: @@
+Note that currently '''no single format can be considered best for all applications'''. Rather, the best format depends on the ''intended use'', as well as a number of other factors (such as licensing and file structure). For example, Shorten and FLAC are widely used for sharing live music because of their cross-platform support and speed. Monkey's Audio is popular among Windows users for its superior compression ratio.
-Note that currently no single format can be considered best for all applications. Rather, the best format depends on the intended use, as well as a number of other factors (such as licensing and file structure). For example, Shorten and FLAC are widely used for sharing live music because of their cross-platform support and speed. Monkey's Audio is popular among Windows users for its superior compression ratio.
 Lossless compressors comparisons (note the specific assumptions and limitations of each comparison; in particular, results are sensitive to the music selected):
@@ Line 104: / Line 108: @@
 ; http://home.wanadoo.nl/~w.speek/comparison.htm : Performance Comparison of Lossless Audio Compressors - Compares file size, encode speed, decode speed for [[APE]], [[FLAC]], [[LPAC]], [[WavPack]], Shorten ([[SHN]]), [[RKAU]], [[OptimFROG]], [[LA]], [[WMA | WMA Lossless]]. Updated 5-2003
-; http://www.firstpr.com.au/audiocomp/lossless/ : Includes a variety of notes, but the testing was completed in 2000, making the results largely obsolete.